Pyrolysis and gasification of meat-and-bone-meal: Energy balance and GHG accounting

Meat-and-bone-meal (MBM) produced from animal waste has become an increasingly important residual fraction needing management. As biodegradable waste is routed away from landfills, thermo-chemical treatments of MBM are considered promising solution for the future. Pyrolysis and gasification of MBM were assessed based on data from three experimental lab and pilot-scale plants. Energy balances were established for the three technologies, providing different outcomes for energy recovery: bio-oil was the main product for the pyrolysis system, while syngas and a solid fraction of biochar were the main products in the gasification system. These products can be used – eventually after upgrading – for energy production, thereby offsetting energy production elsewhere in the system. Greenhouse gases (GHG) accounting of the technologies showed that all three options provided overall GHG savings in the order of 600–1000 kg CO₂-eq. per Mg of MBM treated, mainly as a consequence of avoided fossil fuel consumption in the energy sector. Local conditions influencing the environmental performance of the three systems were identified, together with critical factors to be considered during decision-making regarding MBM management.     

Farmer typology, future scenarios and the implications for ecosystem service provision: a case study from south-eastern Spain

Farming communities are increasingly expected to manage their agricultural activities in ways that ensure sustainable flows of a wide range of ecosystem services for society. The land use and management choices that farmers make are dependent upon their socio-economic characteristics and background, and in turn have important implications for the landscape and associated ecosystem services. Thus, a better understanding about the linkages between the characteristics of farmers, farm management and land use is important for managing multifunctional agro-ecosystems. In this paper, we first develop a typology of farmers for Torrealvilla catchment in Murcia, Spain, according to the characteristics of their households and farm management (e.g. the farmer’s age, household income, water access, land tenure and farm labour). This analysis distinguishes six types of farmers. Secondly, we analyse the link between farmer typology and the farmers’ responses to a number of scenarios. The scenarios describe different likely changes to agriculture in the catchment in terms of environmental constraints (irrigation water availability and rainfall pattern) and environmental policy regulation (water taxation and subsidies). This exercise enables us to explore the range of future land use changes that are likely to occur in the study area. The results indicate that: rain-fed agriculture is expected to experience gradual but extensive abandonment; vegetable/fruit farming and pig/animal rearing are likely to stagnate or even decline; and growing of grapes is likely to expand. Thirdly, we qualitatively evaluate how future land use changes are likely to affect key ecosystem services in the study area including future agricultural production and associated local income generation, erosion control, maintenance of the groundwater table and various cultural services associated with a heterogeneous agro-ecosystem. Particular changes such as expansion of grape production will increase food production and local income at the cost of further depletion of the aquifer and increased risk of salinisation. The outcomes of the study highlight that, to be effective, the design of agri-environmental schemes and other government interventions (e.g. specific compulsory regulations on farming practices and associated water use) should carefully take into account the characteristics of the farmers within the area of interest, their land uses and the possible diversity of responses to policy and environmental drivers. Opportunities exist for future studies quantifying the extent of the impacts of ecosystem service provision through formal models combining farmers’ land use decision-making and spatially explicit modelling of landscape processes.     

Environmental Indicators of Biofuel Sustainability: What About Context?

Indicators of the environmental sustainability of biofuel production, distribution, and use should be selected, measured, and interpreted with respect to the context in which they are used. The context of a sustainability assessment includes the purpose, the particular biofuel production and distribution system, policy conditions, stakeholder values, location, temporal influences, spatial scale, baselines, and reference scenarios. We recommend that biofuel sustainability questions be formulated with respect to the context, that appropriate indicators of environmental sustainability be developed or selected from more generic suites, and that decision makers consider context in ascribing meaning to indicators. In addition, considerations such as technical objectives, varying values and perspectives of stakeholder groups, indicator cost, and availability and reliability of data need to be understood and considered. Sustainability indicators for biofuels are most useful if adequate historical data are available, information can be collected at appropriate spatial and temporal scales, organizations are committed to use indicator information in the decision-making process, and indicators can effectively guide behavior toward more sustainable practices.     

Adjustment of female reproductive investment according to male carotenoid-based ornamentation in a gallinaceous bird

Carotenoid-based ornaments (many yellow–orange–red colourations) may signal the genetic or parental quality of the bearer. Thus, their expression could influence the amount of resources/energy that the mate will invest in the production of offspring, thereby optimising its reproductive fitness. The differential allocation hypothesis (DAH) predicts that females mated with more attractive males should lay more and better eggs. This has been explored only in few bird species with carotenoid-based traits. We tested this hypothesis in the red-legged partridge (Alectoris rufa), a gallinacean with very variable laying capacity. Both sexes display carotenoid-based ornamentation that gradually fades throughout the laying period. Here, the redness of beak and eye rings of captive males was intensified after mating by means of paint. The proportion of females that laid eggs did not differ between treatments. Amongst laying females, those mated with colour-enhanced males (experimental females) tended to lay earlier and produced significantly more eggs than controls, but of similar quality (egg mass and composition). We additionally investigated whether male attractiveness influenced egg components depending on the clutch size and laying sequence. The testosterone level in eggs from experimental females was positively related to the laying order, whereas control eggs did not show any trend. Our results provided mixed support for the DAH, but nevertheless revealed that female red-legged partridges may adjust their breeding investment according to male carotenoid-based ornamentation.     

Biological activity and environmental impact of anionic surfactants

The newest results concerning the biological activity and environmental fate of anionic surfactants are collected and critically evaluated. The chemical and physicochemical parameters related to the biological activity and the field of application are briefly discussed. Examples on the effect of anionic surfactants on the cell membranes, on the activity of enzymes, on the binding to various proteins and to other cell components and on their human toxicity are presented and the possible mode of action is elucidated. The sources of environmental pollution caused by anionic surfactants are listed and the methods developed for their removal from liquid, semiliquid and solid matrices are collected. Both the beneficial and adversary effects of anionic surfactants on the environment are reported and critically discussed. It was concluded that the role of anionic surfactants in the environment is ambiguous: they can cause serous environmental pollution with toxic effect on living organisms; otherwise, they can promote the decomposition and/or removal of other inorganic and organic pollutants from the environment. The relationship between their chemical structure, physicochemical parameters, biological activity and environmental impact is notwell understood. A considerable number of data are needed for the development of new anionic surfactants and for the successful application of the existing ones to reduce the adversary and to promote beneficial effects.     

Environmental psychology in Venezuela

Environmental psychology is a new discipline in Venezuela, which is developing together with, and in response to, the conditioning social and political background of the country. A review of this background and an analysis of the present status of scientific research in the field is presented. The most frequent, and the most neglected, research fields are considered in addition to the principal direction found presently in university education, which will help to determine the formation of future professionals. It is concluded that research in the field is increasing in terms of frequency and variety of themes despite its brief history in the country.     

Fate of the fungicide dodemorph during anaerobic digestion of biological waste

The aim of this study was to examine the stability and distribution of the fungicide dodemorph during anaerobic digestion of biological waste, including a short subsequent aerobic treatment. Three reactor experiments were conducted. The influences of pH and dissolved organic carbon (DOC) were further studied in batch experiments. The reactor experiments showed no decrease in the concentration of dodemorph, indicating stability of the fungicide. In connection with the results of the batch experiments, a clear pH-dependency of the partitioning of dodemorph between solid and water phase could be shown. At pH values below the pK(a) value of 7.8, protonated dodemorph molecules predominate. However, a release into the water phase was only observed at pH values of 5 and below. It can be assumed that in the pH range between 5 and 7.8 dodemorph forms bonds with carboxyl groups of organic matter. Dodemorph was not completely extractable from the solid waste matrix due to strong bonds with the organic matter. Solubilising effects by water ingredients of the process water were not apparent.     

Removal of synthetic dyes from wastewaters: a review

The more recent methods for the removal of synthetic dyes from waters and wastewater are complied. The various methods of removal such as adsorption on various sorbents, chemical decomposition by oxidation, photodegradation, and microbiological decoloration, employing activated sludge, pure cultures and microbe consortiums are described. The advantages and disadvantages of the various methods are discussed and their efficacies are compared.     

National and global greenhouse gas dynamics of different forest management and wood use scenarios: a model-based assessment

An increased use of wood products and an adequate management of forests can help to mitigate climate change. However, planning horizons and response time to changes in forest management are usually long and the respective GHG effects related to the use of wood depend on the availability of harvested wood. Therefore, an integral long-term strategic approach is required to formulate the most effective forest and wood management strategies for mitigating climate change.The greenhouse gas (GHG) dynamics related to the production, use and disposal of wood products are manifold and show a complex time pattern. On the one hand, wood products can be considered as a carbon pool, as is the forest itself. On the other hand, an increased use of wood can lead to the substitution of usually more energy-intense materials and to the substitution of fossil fuels when the thermal energy of wood is recovered. Country-specific import/export flows of wood products and their alternative products as well as their processing stage have to be considered if substitution effects are assessed on a national basis.We present an integral model-based approach to evaluate the GHG impacts of various forest management and wood use scenarios. Our approach allows us to analyse the complex temporal and spatial patterns of GHG emissions and removals including trade-offs of different forest management and wood use strategies. This study shows that the contributions of the forestry and timber sector to mitigate climate change can be optimized with the following key recommendations: (1) the maximum possible, sustainable increment should be generated in the forest, taking into account biodiversity conservation as well as the long-term preservation of soil quality and growth performance; (2) this increment should be harvested continuously; (3) the harvested wood should be processed in accordance with the principle of cascade use, i.e. first be used as a material as long as possible, preferably in structural components; (4) waste wood that is not suitable for further use should be used to generate energy. Political strategies to solely increase the use of wood as a biofuel cannot be considered efficient from a climate perspective; (5) forest management strategies to enhance carbon sinks in forests via reduced harvesting are not only ineffective because of a compensatory increase in fossil fuel consumption for the production of non-wooden products and thermal energy but also because of the Kyoto-“cap” that limits the accountability of GHG removals by sinks under Article 3.3 and 3.4, at least for the first commitment period; (6) the effect of substitution through the material and energy use of wood is more significant and sustained as compared with the stock effects in wood products, which tend towards new steady-state flow equilibria with no further increase of C stocks; (7) from a global perspective, the effect of material substitution exceeds that of energy recovery from wood. In the Swiss context, however, the energy recovery from wood generates a greater substitution effect than material substitution.